Question

Name the different components of xylem and phloem?

Answer 1

Xylem and phloem collectively form the conducting tissues of the plant. These are parenchymatous vascular tissues that help in water and nutrients transport. The xylem is specialized to conduct water from roots and is also called wood. The phloem is specialized in food transport and storage.

Complete answer: Xylem and phloem form the conductive system in plants. These are vascular tissues that help in the transportation of various nutrients and water from the soil throughout the plant. They are parenchymatous vascular tissues. They collectively form vascular bundles and works in coordination as a single unit. The movement of water through the xylem is unidirectional that is from the soil towards the plant in an upside manner. On the other hand, the movement of food or nutrients in the phloem is bidirectional as food needs to be transported from one plant part to another when needed.
Let us first discuss xylem in detail.
Xylem is made up of various elements namely tracheids, vessel elements, xylem parenchyma, and xylem fibers. Let us discuss each element of xylem in detail.
1.Tracheids- These are tube-like cells having tapering ends. They are dead cells having thick lignified walls. They lack protoplasm. Their function is to conduct water.
2.Vessels- These are long cylindrical tube-like structures having lignified walls. They have a large central cavity and lack protoplasm as they are dead. They also help in water conduction and provide mechanical strength to the plant.
3.Xylem Parenchyma- These are living cells of xylem tissue and helps in starch storage. They aid in short-distance travel of water.
4.Xylem fibers- These are lignified dead cells having a central lumen. They function to provide mechanical strength to plants and help in the transportation of water and minerals.

Phloem is also made up of various elements that are companion cells, sieve tubes or sieve cells, phloem parenchyma, and phloem fibers. Let us discuss each element in detail.
1.Companion cells- Companion cells are associated with sieve tubes. They share a common origin with sieve cells and play an important role in the functioning of sieve tubes. They are densely cytoplasmic and nucleated cells. They form a route for sucrose transportation to nearby cells.
2.Sieve cell or sieve tubes- These are the conducting elements of phloem. They are characterized by the absence of nuclei from mature protoplasts. Sieve cells form sieve tubes and these are collectively called sieve elements. They help in the translocation of photosynthetic products and store carbohydrates.
3.Phloem parenchyma- These are parallel oriented cells that help in fat and starch storage. These cells accumulate resins, tannins, etc.
4.Phloem fibers- The fibers associated with phloem have specialized interlocked ends that provide mechanical support to plants. They help in protecting the inner tissues of plants like cambium.
Hence, above are the different components of xylem and phloem.

Note: The xylem and phloem differ greatly based on their functions. The xylem is responsible for replacing the total amount of water molecules lost through transpiration and photosynthesis. On the other hand, phloem is responsible for transporting proteins. Also, phloem functions to carry mRNAs throughout the plant.